Medical ventilator design details

From vacuums to ventilators

Gtech Ventilator Press Release, March 22nd, 2020.

March 22nd, 2020.

Learn about the development of the ventilator, and watch it in action in the video above.

Gtech is making public, design details of a medical ventilator which could be manufactured in a matter of days to help in the fight against COVID-19.

A video of the ventilator working was presented to the government and NHS alongside video drawings and parts.

Nick Grey, Owner of Gtech began working on the project after being contacted by Gareth Rhys Williams, Government Chief Commercial Officer in the early hours of Sunday, March 15th.

“At first I thought it was a hoax – being asked if I could assist in making up to 30,000 medical ventilators in as little as two weeks” said Nick, “When I realised that this was a genuine need I felt compelled to help”.

Nick spent the day learning how ventilators worked and immediately tasked Gtech’s engineering and model making team to tackle the challenge. He also bought a ventilator off eBay and arranged for it to be collected first thing the following morning.

There were quite a lot of problems; oxygen is a very reactive gas, which rules out many motors and electrical devices. Normal air operated cylinders can only run on air, not pure oxygen so they could not be used.

The breakthrough was to repurpose an everyday syringe into an oxygen-powered ram. A valve directs oxygen into the syringe which squeezes a self-inflating air container delivering 400ml of air directly to the patients’ lungs. A second syringe acts as a timer and once the ‘breath’ has been delivered resets the ram ready for the next cycle.

In order to save and conserve oxygen, the waste gas is fed into a reservoir to enrich the patients’ air supply.

The ventilator is driven and controlled entirely from the hospital oxygen supply without the need for electricity.

The number of cycles per minute, volume of air delivered, and the pressure of the air can all be controlled according to patient’s needs.

“We designed the ventilator entirely from parts that can readily be made from stock materials or bought off-the-shelf. This means that if government approves and wants Gtech ventilators they can be made by almost any engineering and manufacturing company” says Nick “Gtech could produce around 100 per day within a week or two providing we could find steel fabrication and CNC machining companies to help us make some of the parts”.

Gtech produced two more ventilators, submitting these to the government for assessment.

Gtech, based in Worcester specialise in making cordless vacuum cleaners and garden power tools.

Learn about the development of the ventilator, and watch it in action in the video above.

Nick Grey and his engineering team with the ventilator - at Gtech’s Worcester headquarters.